Upgrading from an Intel Core i7-2600K: Testing Sandy Bridge in 2019
by Ian Cutress on May 10, 2019 10:30 AM EST- Posted in
- CPUs
- Intel
- Sandy Bridge
- Overclocking
- 7700K
- Coffee Lake
- i7-2600K
- 9700K
Power Consumption
One of the risk factors in overclocking is driving the processor beyond its ideal point of power and performance. Processors are typically manufactured with a particular sweet spot in mind: the peak efficiency of a processor will be at a particular voltage and particular frequency combination, and any deviation from that mark will result in expending extra energy (usually for better performance).
When Intel first introduced the Skylake family, this efficiency point was a key element to its product portfolio. Some CPUs would test and detect the best efficiency point on POST, making sure that when the system was idle, the least power is drawn. When the CPU is actually running code however, the system raises the frequency and voltage in order to offer performance away from that peak efficiency point. If a user pushes that frequency a lot higher, voltage needs to increase and power consumption rises.
So when overclocking a processor, either one of the newer ones or even an old processor, the user ends up expending more energy for the same workload, albeit to get the workload performed faster as well. For our power testing, we took the peak power consumption values during an all-thread version of POV-Ray, using the CPU internal metrics to record full SoC power.
The Core i7-2600K was built on Intel’s 32nm process, while the i7-7700K and i7-9700K were built on variants of Intel’s 14nm process family. These latter two, as shown in the benchmarks in this review, have considerable performance advantages due to microarchitectural, platform, and frequency improvements that the more efficient process node offers. They also have AVX2, which draw a lot of power in our power test.
In our peak power results graph, we see the Core i7-2600K at stock (3.5 GHz all-core) hitting only 88W, while the Core i7-7700K at stock (4.3 GHz all-core) at 95 W. These results are both respectable, however adding the overclock to the 2600K, to hit 4.7 GHz all-core, shows how much extra power is needed. At 116W, the 34% overclock is consuming 31% more power (for 24% more performance) when comparing to the 2600K at stock.
The Core i7-9700K, with eight full cores, goes above and beyond this, drawing 124W at stock. While Intel’s power policy didn’t change between the generations, the way it ended up being interpreted did, as explained in our article here:
Why Intel Processors Draw More Power Than Expected: TDP and Turbo Explained
You can also learn about power control on Intel’s latest CPUs in our original Skylake review:
The Intel Skylake Mobile and Desktop Launch, with Architecture Analysis
213 Comments
View All Comments
amrs - Saturday, May 11, 2019 - link
But what speed of RAM did you stuff it with? Fallout 4 has been shown to benefit from RAM faster than DDR3-1600.Mr Perfect - Monday, May 13, 2019 - link
DDR3-1600, as luck would have it. Do you have a link handy for those benchmarks?Hyper72 - Friday, May 10, 2019 - link
I'm sitting here with an aging Ivy - 3630QM, that can't be overclocked. I'm really dreaming of an upgrade!eek2121 - Saturday, May 11, 2019 - link
Wait for AMD then. Apparently (according to AMD) are going to quadruple (at least for Rome, which uses the same Zen 2 architecture) and only half that is core count.Targon - Sunday, May 12, 2019 - link
What many are expecting from Ryzen 3rd generation at this point: a significant IPC boost(anywhere from 10-15 percent), and potentially 5GHz on 8 or even 12 cores. Not enough information to know if the 16 core version will be able to hit 5GHz on all cores or not right now. Considering that Ryzen 2700X is hitting 4.3GHz on 8 cores, 12 cores@5GHz will be a significant boost combined with the IPC improvements as well.May 27th is soon enough to get the official clocks and core counts, and then we get to wait for independent benchmarks on overclocking on X370, X470, and then X570.
Zoomer - Thursday, June 13, 2019 - link
I see I purchased my SB pricematched to MC in 2011 (thanks NCIX! and RIP). Maybe it'll make it a decade. Will give time for DDR5 to mature. Don't want to be stuck on a platform with obsolete DDR4.StevoLincolnite - Friday, May 10, 2019 - link
I am running Sandy-Bridge-E... So even less of a need to upgrade... 6-cores, PCI-3.0, Quad-Channel DDR3... Overclocks to 5Ghz if I need...I could upgrade, but I haven't reached a point where it's holding me back yet in gaming.
mode_13h - Saturday, May 11, 2019 - link
But if something wants AVX2, you're SOL.StevoLincolnite - Saturday, May 11, 2019 - link
Haven't come across it yet. When that day comes... I imagine it will be the same when I dragged my feet when CPU's with SSE, SSE2, SSE3 and so on came out... I will upgrade when the need arises.mode_13h - Tuesday, May 14, 2019 - link
I think Oculus requires it, as they were fairly explicit in their platform requirements of >= Haswell, which is the first gen with AVX2.